The fire pump has become the most widely used fire pump because of its simple structure, convenient use and maintenance, and high efficiency. However, sometimes the centrifugal fire pump cannot lift water, which is very troublesome. The cause of the failure of the fire pump to lift water is now analyzed.

The speed of the fire pump is too low

(1) Human factors. Due to the damage of the original motor, a considerable number of users randomly equipped the fire pump with another motor to drive it. As a result, the flow rate was low, the head was low, and even the water could not be pumped.

(2) The transmission belt is worn. There are many large-scale isolated fire pumps that use belt transmission. Due to long-term use, the drive belt is worn and loosened, and slipping occurs, thereby reducing the speed of the fire pump.

(3) Improper installation. The distance between the centers of the two pulleys is too small or the two shafts are not parallel, the fire pump transmission belt is installed on the tight side, resulting in too small wrap angle, the calculation error of the diameter of the two pulleys, and the large eccentricity of the two shafts of the fire pump driven by the shaft, etc. Both will cause changes in fire pump speed.

(4) Mechanical failure of the fire pump itself. The fastening nut between the impeller and the pump shaft is loose or the pump shaft is deformed and bent, causing the impeller to move more, directly rubbing against the pump body, or the bearing is damaged, which may reduce the speed of the fire pump.

(5) Improper maintenance of fire pump power machine. The motor loses its magnetism due to the burning of the windings, the number of winding turns, wire diameter, and wiring method changes during maintenance, and the failure of the fire pump or maintenance to completely eliminate factors will also change the speed of the fire pump.

The second way to solve the fire pump failure:

Some users have measured that although the vertical distance from the water reservoir or water tower to the water surface of the fire pump is slightly smaller than the lift of the fire pump, the water capacity is still small or cannot be lifted. The reason for the fire pump is often that the pipeline is too long, there are many bends in the water pipe, and the resistance loss of the water flow in the pipeline is too large. The reason is often that the pipeline is too long, there are many bends in the water pipe, and the resistance loss of the water flow in the pipeline is too large. In general, the resistance of the 90-degree elbow is greater than that of the 120-degree elbow, and the head loss of each 90-degree elbow is about 0.5 to 1 meter, and the resistance of each 20-meter pipe can cause a head loss of about 1 meter. In addition, some users also choose the diameter of the inlet and outlet pipes of the fire pump at will, which also has a certain impact on the lift.

(1) Some users do not fill enough water before starting the fire pump; sometimes it seems that the filled water has overflowed from the vent hole, but the air is completely discharged without turning the pump shaft, resulting in a little air remaining in the water inlet pipe or pump body middle.

(2) The horizontal section of the inlet pipe that is in contact with the fire pump shall apply a descending slope of more than 0.5% against the direction of water flow, and the end connected to the inlet of the fire pump shall be the highest, and shall not be completely horizontal. If it is tilted up, air will remain in the water inlet pipe, which will reduce the vacuum in the water pipe and fire pump, and affect water absorption.

(3) The packing of the fire pump has been worn out due to long-term use or the packing is too loose, causing a large amount of water to spray out from the gap between the packing and the pump shaft sleeve. As a result, the external air enters the fire pump from these gaps. The inside of the pump, which affects the pumping of water.

(4) The water inlet pipe has been underwater for a long time, and the pipe wall has corroded holes. After the fire pump works, the water level continues to drop. When these holes are exposed to the water surface, air enters the water inlet pipe through the holes.

The flow value of the stabilized pump depends on many factors, the main ones are:

(1) Type of system When the stabilized pump is used in a self-spray system, consider the water volume of a sprinkler; and when it is used in a fire hydrant system, consider the water volume of a fire hydrant.

(2) When there is an air pressure water tank and an air pressure water tank, the flow rate of the pressure stabilizing pump is not greater than the water volume of a nozzle or a fire hydrant. When there is an air pressure water tank, the water supply and pressure guarantee of the system are implemented by the air pressure water tank, and the flow rate of the pressure stabilizing pump only needs to meet the flow requirements of the air pressure water tank, that is, the flow rate of the pressure stabilizing pump should take into account the pressure of the air pressure water tank. Factor for adjusting the volume of the tank. At this time, the flow rate of the pressure stabilizing pump should be calculated and determined according to the calculation formula of the total volume of air and water in the tank of the air pressure water supply equipment and the volume of water in the tank. The water output of the water pump should be not less than 1.2 times the hourly flow of the pipe network when the tank is at the average pressure.

There is no provision in the "High Regulations" that the air pressure water tank must be equipped, but without the air pressure water tank, the voltage stabilizing pump starts frequently and is easy to be damaged; with the air pressure water tank, the problem of the pressure stabilizing pump starting frequently can be alleviated, and the voltage stabilization work of the system can be alleviated. The guarantee of the situation can be better reflected. However, the cost of the air pressure water tank needs to be increased. In general, the volume of the air pressure water tank provided with the equipment does not need to be too large, and the volume should be less than 50L. Shanghai has compiled a standard atlas of pressure-stabilizing pumps for supporting air-pressure water tanks.

(3) System scope The quasi-high-pressure water supply system (or called the high-pressure water supply system) with a stabilizing pump can range from indoor to indoor and outdoor. Indoor quasi-high pressure water supply system, the pipe is made of steel pipe, and the interface is connected by thread, flange or welding. The leakage of the pipe network system mainly occurs in the sealing part of the water pump, and its quantity is relatively limited. In the indoor and outdoor quasi-high pressure water supply system, since the outdoor pipes are made of cast iron, the interface adopts socket connection, and the interface seal adopts rubber ring. Immediately after the construction of the pipeline, the soil is covered, and sometimes the interface is reinforced with concrete enclosure. Even if there is leakage, it is difficult to take remedial measures. All these show that when the quasi-high pressure water supply system is used indoors and outdoors, there should be enough room for the flow rate of the stabilizing pump.

Fire pump experts are improving and perfecting the previously used fire pumps. New fire pumps have begun to come into people's sight, and now they have become a very common fire pump. Then you should pay more attention to some aspects when using this kind of fire pump, because there are many functions added to this kind of fire pump, so it may not be compatible with other equipment, and of course there will be some big and small problems. When using fire pumps, many people report that this kind of fire pump often consumes too much power, so what should be done when this phenomenon occurs, let’s take a look at the two possible reasons below.

1. The impeller is faulty

When the XBD fire pump consumes too much power, one of the things that should be considered is that the impeller is faulty, which must be considered first. This kind of failure may occur when the rotation direction of the impeller is incorrect, then the rotation direction of the impeller should be corrected before working. In addition, if the impeller is damaged, then the impeller with bad track should be replaced in this case.

2. Defects in rotating parts

Another reason for excessive power consumption when using an XBD fire pump is that there may be a big problem with the rotating parts. However, when the rotating parts are seized, the power consumption will be too large, so these should check whether the internal wear of the rotating parts is normal. It can also be that the rotating bearing is bent, then the shaft should be corrected or replaced directly.


The inlet medium of the fire pump is insufficient or the water inlet pressure is not enough, or the water inlet pipe of the fire pump is blocked, or the air in the fire pump cavity is not exhausted. When the fire pump is idling, the impeller has no contact or little contact with the medium, so it cannot work effectively, and the liquid cannot be delivered normally. These are all useless work. Because there is no effective work, the load on the motor is very small, and the current generated is also very small, so there will be no impact on the motor. The impact of idling on the fire pump is indeed fatal to the pump. Idling fire pumps are prone to cavitation, causing damage to the pump body and flow-through parts; idling fire pumps with mechanical seals or packing seals will not be lubricated by liquid, resulting in dry grinding and rapid damage; idling fire pumps Fire pump rotor parts and pump body heat up, without liquid cooling, those narrow gaps (such as sealing rings) are easily seized by the action of heat expansion and contraction; the balance plate of an idling multi-stage fire pump is not lubricated by water, and the balance plate Will be burnt and damaged very quickly.

For early warning and maintenance of fire pump idling, it is recommended to improve the design of fire pump:

1. Treat each clearance position of the fire pump and expand it under permissible conditions to prevent seizure;

2. Carry out special process treatment, quenching and tempering, heat treatment, etc. on the shaft of the fire pump to increase the hardness and use low-flexibility materials to prevent it from being seized by large swings during idling;

3. Use mechanical seals and packing chambers that do not need to be lubricated by liquid media;

4. Choose closed self-lubricating bearings without oiling.

Compared with other fire pumps, the pump cavity of the horizontal self-priming fire pump has a larger space, and there is a place where water can be stored. Before the self-priming fire pump works normally, the cavity should be filled with liquid, and there is a period of self-priming before operation. During this period, the air is continuously discharged out of the pump body. This period is partly idling.

Regular maintenance and maintenance are indispensable for any mechanical equipment, so as to better account for the good operation of the equipment and promote the equipment to have a longer service life, and the fire pump equipment is no exception. zjbetter recommends that you read the manual provided by the manufacturer if conditions permit before overhaul and maintenance, which can better promote the maintenance of the equipment. The following are related precautions for fire pump maintenance introduced by zjbetter.

When dismantling:
1. When removing the thrust bearing, record the clearance of the balance disc;
2. When disassembling the multi-stage pump, the parts can be marked in sequence for better reassembly;
3. When disassembling, pay attention to avoid bumping and damaging parts, and ensure that parts are in good condition.
Parts maintenance:
1. Check whether the surface of each part is normal and intact, without bumps, scratches, rust, etc.;
2. Use measuring tools to measure whether the tolerance of some key matching parts is qualified;
3. Measure the clearances of the impeller seal ring, guide vane seal ring, and interstage bushing housing seal ring. If the gap is not within the allowable range and the wear is serious, it needs to be replaced;
4. Check whether the bearings, sealing rings and gaskets are in good condition and need to be replaced;

Reloading:
1. Install the rotor first, and conduct a dynamic balance test;
2. When reassembling, measure the gap at each sealing ring again to ensure that it is correct;
3. Before installing the balance disc, the total string volume of the rotor needs to be measured;
4. After installing the balance plate, measure the rotor half string volume.
6. Fasten all bolts;
7. Suction a dial indicator on the shaft, and rotate the shaft to measure the balance disc. The tolerance is generally required to be less than 0.06;
8. When installing the thrust bearing, pay attention to adjusting the clearance of the balance disc, and use the adjusting ring in front of the fire pump bearing to adjust the clearance of the balance disc to the drawing requirements.

This problem, in short, is the selection of water pumps. The following are the relevant steps for you to choose water pumps from zjbetter. I hope they can help you choose water pumps and help you better. Choose the water pump that suits your project.

1. Confirm the use environment
First understand the environment in which the equipment is used, including temperature, humidity, air pressure, air corrosiveness, dustproof and waterproof requirements, and the level of hazardous areas.
2. Confirm operating conditions
Refers to the liquid surface pressure (absolute) on the suction side of the liquid, the liquid surface pressure on the discharge side, intermittent or continuous work, fixed or mobile position, and the convenience of installation and maintenance.
3. Confirm the nature of the medium
Medium temperature, density, viscosity, saturated vapor pressure, solid particle diameter and content, gas content, corrosiveness, volatility, explosiveness, toxicity.
4. Select the material of the pump wetted parts
According to the physical and chemical properties of the pumped medium above, the material of the flow-passing parts is determined.
5. Determine performance parameters
The performance parameters of the water pump can be determined by calculation, analogy, test and other methods.
6. Determine the installation type
The installation of the pipeline is determined by the layout of the pipeline and the installation site, and there are direct connection, vertical and other types.
8. Determine the number of pumps
In general, spare pumps, especially fire pumps, are set up, and the number of pumps is selected according to different situations.

Fire protection is very important to people's life, which is related to the safety of people's lives and properties. In order to ensure people's fire safety, the government not only has 119 fire alarms, but also has higher requirements for the fire fighting equipment systems of various units. A set of safe and qualified fire-fighting equipment can save people's lives in such critical moments as a fire. The fire pump is a kind of either use it or not, once it is used, its value is far beyond its own. So what fire pump equipment is the safest and most secure?

We all know that when a fire occurs, various situations may occur, the circuit may be damaged, and the equipment may malfunction temporarily. In order to deal with these unexpected factors, fire pump manufacturer zjbetter has developed and produced a relatively safe and guaranteed The equipment, yes, is the fire pump unit.

The main feature of the fire pump set is that it has two kinds of power control, which are diesel engine and electric motor. The electric pump set is put into operation when the mains power is normal. When the power supply fails and the electric fire pump cannot be put into use normally, the diesel engine fire pump set will be put into operation automatically to ensure the supply of fire water. The diesel engine fire pump set can also be equipped with various automatic fire pumps. Function, meet the requirements of the standard, ensure the long-term normal standby state of the equipment, and put it into fire fighting work at any time. The two power supply methods are more reliable to ensure the fire water supply in case of fire emergency.

Zjbetter fire pumps have a wide range of applications, and are suitable for various fire hydrants, sprinkler fire main pumps, fire booster pumps, various villas, residential areas, industrial and civil buildings and other fire protection systems, as well as various oil depots, oil loading and unloading Ports, logistics parks and other places with high fire protection requirements.

The long shaft fire pump is the choice of many customers and plays an important role in people's fire safety. Of course, in order to better play its role, as well as better use and maintain the water pump, some precautions about the long-axis fire pump still need your attention.

Since the fire pump plays a very important role and is related to people's fire safety, when some problems occur during use, it must be paid attention to, so as not to delay the normal use of the fire pump, so that it cannot be started in time when a fire occurs, and the fire extinguishing time is delayed. . When a problem is found, it must be repaired immediately to eliminate the fault and ensure that the equipment is safe and effective before it is put into use, so as to better ensure people's fire safety.
The packing seal is an important part of the water pump. During the use of the fire pump, it is necessary to pay attention to the condition of the packing seal regularly and add it in time, otherwise it will affect the sealing performance of the water pump. Once the fire pump causes water leakage, it will directly affect the power consumption of the motor of the equipment, which will greatly increase the power consumption and damage the impeller of the equipment.
When the equipment generates strong vibration during operation, it is necessary to stop the operation of the equipment, check and repair the fire pump, and eliminate the problem, so as not to cause greater damage to the pump.
Secondly, the impeller is also a relatively important part in the water pump, and the condition of the impeller should be paid attention to regularly when the water pump is running. Regularly check whether there are cracks on the impeller of the water pump, and pay attention to the rust of the impeller. The cracks or rust of the impeller may cause damage and lead to the normal operation of the pump. In addition, in the daily maintenance of the fire pump, it is also necessary to pay attention to whether the fixing of the impeller is loose. At the same time, the mud needs to be repaired regularly to avoid blockage and affect the operation of the pump.
When using a long-axis vertical fire pump, there are still many things that need to be paid attention to. In order to better maintain the water pump and prolong its service life, daily professional maintenance is very important. Shanghai Xizhiquan is a professional fire pump manufacturer. The company produces a complete range of equipment, including fire booster and voltage regulator equipment, diesel engine fire pump sets, single-stage one-stage multi-stage fire pumps, fire control cabinets, etc. Since its establishment 19 years ago, the company has accumulated rich experience in pre-sales and after-sales, guaranteeing high-quality services for customers.